1. Field of the Invention
The present invention relates to a nozzle plate formed with a plurality of nozzles, a method for producing the nozzle plate, and a method for producing an ink-jet head provided with the nozzle plate.
2. Description of the Related Art
A certain ink-jet head for discharging an ink from nozzles is known, wherein a plurality of plates, which include a nozzle plate formed with the nozzles, are stacked to one another, and thus ink flow passages, through which the ink is allowed to flow, are formed. For example, in an ink-jet head described in Japanese Patent Application Laid-open No. 2006-305767, five plates in total, i.e., a nozzle plate formed of a synthetic resin material, a base plate, a manifold plate, a spacer plate, and a cavity plate each formed of a metal material are stacked to one another, and they are joined or bonded to one another by an adhesive. A cavity unit (flow passage unit), which has ink flow passages ranging from an ink supply port via pressure chambers to nozzles, is constructed by these plates.
However, in the case of Japanese Patent Application Laid-open No. 2006-305767, the five plates are joined to one another by the adhesive in such a state that through-holes, which serve as the ink flow passages including, for example, the nozzles and the pressure chambers, are formed. Therefore, it is feared that the adhesive may protrude into the ink flow passage through any gap between the plates, and the discharge characteristic of the ink to be discharged from the nozzle may be consequently changed. In view of such a circumstance, the following procedure may be also conceived in order that the five plates are joined or bonded to one another without using the adhesive. That is, for example, the nozzle plate is also formed of a metal material in the same manner as the other four plate, and the five plates are joined to one another by the diffusion bonding or diffusion joining. However, in this procedure, it is difficult to perform the processing in order that minute nozzles are formed in the nozzle plate formed of the metal material.